Lower esters represented by ethyl acetate have been used in large quantities as paint solvents, extracting solvents, intermediates for chemical products and medicines, or the like, and are important materials in the chemical industry.
Such lower esters have conventionally been produced by dehydrating esterification from carboxylic acids and alcohols or condensation of aldehydes which is called Tishchenko reaction. In recent years, a process for the production of esters from carboxylic acids and olefins using a heteropolyacid catalyst has been reported (JP-A 5-65248, etc.) and noted as a new process for producing ethyl acetate.
In prior art processes for the production of ethyl acetate, however, plural raw materials such as acids and alcohols or acids and olefins have been used and thus the procurement of plural sources for the raw materials has been required, or otherwise, raw materials such as acetaldehyde, which are not easy to procure in a non-industrial area and difficult to handle, have been used and thus procuring, stockpiling and handling the raw materials have not been easy.
For the manufacture of esters having different carbon chain lengths, dehydrating esterification from the corresponding acids and alcohols has been effective means. However, there has been a problem of corrosion of an apparatus, etc., since acids are used as raw materials.
A process for producing ethyl acetate from ethyl alcohol by oxidative esterification using a palladium catalyst is reported in Kogyou Kagaku Zasshi, vol. 71, No. 9, pages 1517–1522, 1968. JP-A 9-29099 discloses a process for producing an ester from an alcohol and an aldehyde by a palladium-lead catalyst. In these reactions which consume oxygen, however, industrially useful hydrogen is not utilizable as by-product, although esters are produced.